• Journal of dental hygiene science
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• v.9 no.2
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• pp.169-179
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• 2009

This study aims to present a fundamental data base to figure out the mental and the physical conditions that the dental technicians are facing and ultimately to develop a health care program to deal with their health related problems. To this end, we took an analysis on the health status among the subjects of 895 dental technicians currently working at the dental lab around the nation from January 15 to March 31, 2009 by way or Todai Health Index(THI). Of the average scale point in accordance with 12 scale scores of the physical and the mental subjective symptom, the results revealed that the physical appeals (21.10) were higher than the mental appeals (18.49) and the multiple subjective symptom was marked as 38.44 followed by the mental irritability (25.92). In gender differences, the females proved to be higher than the males in both physical appeals and mental appeals while the physical appeals were dominant in both genders. The physical appeals were higher than the mental appeals with regard to the general characteristics. In the case or the group or age twenties as shown in the physical and mental average scale point, the other groups showed 21.55% of the physical appeals among the married whereas the mental appeals showed the highest point as 18.70 in the unmarried group. In job position, the other groups marked the highest, in working condition, below average group marked the highest, in frequency of break time, none group marked the highest. We drew a conclusion form this study that the dental technicians gained the higher points in the item or the multiple subjective symptom, the menial irritability, and the irregular life. More research on th is phenomena should be followed along with the development of various and practical health care programs to promote the health or dental technicians.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.374-381
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• 2015

Occurrences of coastal dredged materials are ever increasing due to port construction, navigational course maintenance and dredging of polluted coastal sediments. Ocean dumping of the coastal dredged materials has become virtually prohibited as London Treaty will be enacted as of the year 2012. It will be necessary to treat and recycle the dredged materials that may carry organic pollutants and heavy metals in a reasonable and effective process: collection of the dredged materials, liquid and solid separation, and treatment of organic compounds and heavy metals. In this study we have developed a continuous bioreactor system that can treat a mixture of silt and particulate organic matter using a microbial consortium (BM-S-1). The steady-state operation conditions were: pH (7.4-7.5), temperature ($16^{\circ}C$), DO (7.5-7.9), and salt concentration (3.4-3.7%). The treatment efficiencies of SCOD, T-N and T-P of the mixture were 95-96%, 92-99%, and 79-97%. The system was also effective in removal of heavy metals such as Zn, Ni, and Cr. Levels of MLSS during three months operation period were 11,000-19,000 mg/L. Interestingly, there was little sludge generated during this period of operation. The augmented microbial consortium seemed to be quite active in the removal of the organic component (30%) present in the dredged material in association with indigenous bacteria. The dominant phyla in the treatment processes were Proteobacteria and Bacteroidetes while dominant genii were Marinobacterium, Flaviramulus, Formosa, Alteromonadaceae_uc, Flavobacteriaceae_uc. These results will contribute to a development of a successful bioremediation technology for various coastal and river sediments with a high content of organic matter, inorganic nutrients and heavy metals, leading to a successful reuse of the polluted dredged sediments.